14 H+ + 6 Fe2+ + Cr2O72- . 2 Cr3+ + 6 Fe3+ + 7 H2O This reaction is used in the
titration of an iron solution. What is the concentration of the iron solution if it takes 45.20 mL
of 0.1000 M Cr2O72- solution to titrate 50.00 mL of an acidified iron solution?
a.
0.5424 M
b.
0.1000 M
c.
1.085 M
d.
0.4520 M
e.
0.2712 M

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.